Percentile "advantage" system

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Sosthenes

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I'm really fond of BRP-ish percentile systems, but I do understand that for some people doing double digit calculations for modifiers etc.
This was part of what people always complained about Rolemaster...

Now D&D 5E introduced the advantage mechanic, which seems to solve a similar issue. Roll 2d20, pick the best, reverse for disadvantage.

Can we do something similar for percentile dice, roll-under style?

1. Sure, rolling two sets of percentile dice would be the obvious solution. I don't quite like grabbing 4d10 and keeping them separate, or else I wouldn't be writing this post. Can be solved by special dice (tens and ones dice, two sets with different colors).
2. Grab three dice, one is always the ones, but you can pick the better tens.
3. Just two dice, but you can swap.
4. ???

I've seen (3) somewhere, and there's a rpg.net post with the maths worked out. Seems to be quite similar to d20 advantage, with the middle range of percentile stats/skills benefitting most.

Any ideas and opinions about this?
 
If I can take the best between original roll and re-roll, this would only save me one roll if I already critically succeed with the first one. And thus would be pretty much identical to "two pairs of d00".
 
Why not just use re-rolls?
While they're mechanically identical, "advantage" and "reroll then take best" have different table feels. Rerolls come with the risk of getting a lower number on the reroll, which feels bad to see, whereas with advantage rolls you're getting to just throw away the worst die and that feels fun. Personally I think that makes advantage the better mechanic in almost any situation.
I'm really fond of BRP-ish percentile systems, but I do understand that for some people doing double digit calculations for modifiers etc.
This was part of what people always complained about Rolemaster...

Now D&D 5E introduced the advantage mechanic, which seems to solve a similar issue. Roll 2d20, pick the best, reverse for disadvantage.

Can we do something similar for percentile dice, roll-under style?

1. Sure, rolling two sets of percentile dice would be the obvious solution. I don't quite like grabbing 4d10 and keeping them separate, or else I wouldn't be writing this post. Can be solved by special dice (tens and ones dice, two sets with different colors).
2. Grab three dice, one is always the ones, but you can pick the better tens.
3. Just two dice, but you can swap.
4. ???

I've seen (3) somewhere, and there's a rpg.net post with the maths worked out. Seems to be quite similar to d20 advantage, with the middle range of percentile stats/skills benefitting most.

Any ideas and opinions about this?
Personally I always roll percentiles with percentile dice, so picking up two sets (Or a set plus an extra tens die) feels like the easiest to me, so I'd go with (2). It also reverses neatly enough for disadvantage.

iirc Unknown Armies uses (3).
 
Call of Cthulhu 7E has a advantage/disadvantage system. They just call it bonus and penalty dice.
Basically, when you have advantage you roll an extra "tens" die and take the best result. In that game you can even double advantage/disadvantage. Advantage/Disadvantage still cancel each other, just like in D&D5.
 
Mythras offers rerolls and value swaps with luck points, though their rerolls don’t specify taking the best one.

the value swap is extremely strong. My players, and many others, prefer it over all others because you understand the outcomes. I view it as a tool for heroic environments, and less about a lucky normal guy.

mathematically, reroll and taking the best is very close to Mythras’s formidable rating, for middle values.

CoC’s bonus die gives a weird stair stepping effect that I’m not overly fond of. At the point where I am rolling a third die, I might as well have two different colors of dice and roll both at the same time.

I’m largely a fan of just rerolling and taking the best if I want to do this. It’s mechanically the same, it doesn’t skew with prediction.
 
You could just use two differently coloured sets of percentile dice.
Sure, but I generally don't like it when you have to mandate special dice in the rules, or at least when this is a lot more expedient than the default. If your default percentile dice are color-coded already (i.e. no "00-90" dice, but e.g. red for tends, black for ones), it gets quite confusing.

Also likely to play with people here who did The Dark Eye before, so color-coded dice might trigger something ;)
 
I'm really fond of BRP-ish percentile systems, but I do understand that for some people doing double digit calculations for modifiers etc.
This was part of what people always complained about Rolemaster...

Now D&D 5E introduced the advantage mechanic, which seems to solve a similar issue. Roll 2d20, pick the best, reverse for disadvantage.

Can we do something similar for percentile dice, roll-under style?

1. Sure, rolling two sets of percentile dice would be the obvious solution. I don't quite like grabbing 4d10 and keeping them separate, or else I wouldn't be writing this post. Can be solved by special dice (tens and ones dice, two sets with different colors).
2. Grab three dice, one is always the ones, but you can pick the better tens.
3. Just two dice, but you can swap.
4. ???

I've seen (3) somewhere, and there's a rpg.net post with the maths worked out. Seems to be quite similar to d20 advantage, with the middle range of percentile stats/skills benefitting most.

Any ideas and opinions about this?
"Roll two tens dice, and one single-digit one", as used in CoC7e?
 
Zweihander is a percentile roll-under system. They have "flip to succeed/flip to fail", which means roll percentile dice and flip the tens and ones. Whether you do it, or do it for better or worse depends on whether you flip to succeed or fail. Does that make sense?
 
...
Can we do something similar for percentile dice, roll-under style?

1. Sure, rolling two sets of percentile dice would be the obvious solution. I don't quite like grabbing 4d10 and keeping them separate, or else I wouldn't be writing this post. Can be solved by special dice (tens and ones dice, two sets with different colors).
2. Grab three dice, one is always the ones, but you can pick the better tens.
3. Just two dice, but you can swap.
4. ???

I've seen (3) somewhere, and there's a rpg.net post with the maths worked out. Seems to be quite similar to d20 advantage, with the middle range of percentile stats/skills benefitting most.

Any ideas and opinions about this?
I like 2 and 3. I personally like how on option 3 it doesn't matter much to the highly skilled and does provide a great relative boost to the low skilled but far from providing a guarantee.

A fourth way, assuming this is roll under, replace the tens die with a die type other than d10. You could have levels of advantage where the tens die is a d8, to d6 to d4 to d3 to d2. A disadvantage would be perhaps to replace the tens die with a d12 or even worse d20.

I like to tie this stuff into magic and creatures. Like a minor curse would replace with a d12 and major curse with a d20. Fey my roll a d8 for the tens die because of luck, various magical levels of luck/blessing could progress from a d8 to a d2 for the tens die. I think the game design term I've heard is these are levers, or dials or something. I tend to call it degrees of freedom range for a mechanic, as the die flip had a degree of 2 (one for advantage and one for disadvantage) while the die replace has a degree of 7.

Just another way to do. I like option 3 myself though if you want a basic advantage type system.
 
A fourth way, assuming this is roll under, replace the tens die with a die type other than d10. You could have levels of advantage where the tens die is a d8, to d6 to d4 to d3 to d2. A disadvantage would be perhaps to replace the tens die with a d12 or even worse d20.
This would only work in a straight roll under. In Mythras, for example, this would mean that you would have less chance of winning an opposed roll, as rolls within the same success band are won by the higher roll that is still under skill (price is right, or blackjack). If you are going with a simple roll it might work though.

It would also mean you would have to invent a mode for failure if you relied on, say 96-100, as always failure. And if you gave a high enough skill, you can’t lose (90+ skill, step down that die to a d8+d10 instead of 2d10).

it works pretty well on the other end, as it only introduces new options that are out of normal range (11 or 12)
 
2. Grab three dice, one is always the ones, but you can pick the better tens.

So on anydice

I tried best one out of 3d10 to get a sense of how the odds would skew on the tens.

1631667604456.png

The 50% mark on taking the best 2 out of 3 would make results higher than around 88% more frequent at 50% of the time. So you giving a rough +35% bonus.
 
Zweihander is a percentile roll-under system. They have "flip to succeed/flip to fail", which means roll percentile dice and flip the tens and ones. Whether you do it, or do it for better or worse depends on whether you flip to succeed or fail. Does that make sense?
WFRP has that too... or similar, for use of a Fate point.

Whatever, anything but re-rolls, I hate re-rolling.
 
Nice, didn't know that. Between CoC D20 and ToC, I haven't had the need to look at CoC 7 more than once or twice.

Edit: Oh boy. Pre-calculated normal/hard/extreme values. Bonus and penalty dice. "Pushing". That's a bit much, right?
I don't find it's "a bit much", no. After all, these are just pre-calculated stats with a penalty...and while you have a spot for them on the charsheet, you don't need to actually pre-calculate them. Just calculate them the first time you have a low enough roll (under 15 is my cut-off point) and then write them on the sheet:thumbsup:.


Zweihander is a percentile roll-under system. They have "flip to succeed/flip to fail", which means roll percentile dice and flip the tens and ones. Whether you do it, or do it for better or worse depends on whether you flip to succeed or fail. Does that make sense?

It made sense when we used it in Unknown Armies and Eclipse Phase, why wouldn't it make sense here:grin:?
 
I don't find it's "a bit much", no. After all, these are just pre-calculated stats with a penalty...and while you have a spot for them on the charsheet, you don't need to actually pre-calculate them. Just calculate them the first time you have a low enough roll (under 15 is my cut-off point) and then write them on the sheet:thumbsup:.
I meant that there are three ways a roll is modified: difficulty, bonus/penalty dice and pushing.
 
I meant that there are three ways a roll is modified: difficulty, bonus/penalty dice and pushing.
Pushing isn't a modifier, though.
"I can't find the book myself, I'm running out of time...can I use my best smile on the librarian to present myself as a fellow bookworm to make her actually help me find it?"
If you succeed, you find the book after all. If you fail, the librarian...invites you to leave and never return, I guess? Which might be a bummer for many scenairos.
 
Pushing is closer to a Luck or Effort mechanic more than anything, so it's not the same thing as a situational modifier.

As far as the modifier mechanics go in CoC 7E, any significant advantage to a standard roll simply uses the Bonus Dice mechanic,


The only bit I find to be unclear at times is when a situation has a Disadvantage...

As a GM, do I reduce the required success level (ie: Standard Success dropped to Hard Succeas, etc), or do I ask the PC to instead roll a Penalty Dice?

I guess one is pertaining to intrinsic difficulties, whereas the other is pertaining to circumstantial difficulties.

In practice I have found it easy to determine which mechanic to go with, but I do sometimes find it hard to articulate to others which one to use, so I guess it may be a little daunting for some people.
 
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Pushing isn't a modifier, though.
"I can't find the book myself, I'm running out of time...can I use my best smile on the librarian to present myself as a fellow bookworm to make her actually help me find it?"
If you succeed, you find the book after all. If you fail, the librarian...invites you to leave and never return, I guess? Which might be a bummer for many scenairos.
That doesn't seem like 'pushing' to me... it's not a retry of the same skill, it's a whole different approach to the problem... though I don't think you have to try to seduce a librarian to get one to assist on a book search.
 
That doesn't seem like 'pushing' to me... it's not a retry of the same skill, it's a whole different approach to the problem...
Yeah as far as I know, you may try a different approach, but the actual skill would be the same skill you initially rolled. Except with the risk of a failure causing a serious consequence, akin to an automatic fumble.

Trying a completely different approach would likely involve rolling a new skill. However, depending upon the logics of the situation, there may be a consequence for that particular character returning to the issue, such as now requiring a Hard Success or something like that.

Pushing is for situations not requiring an immediate outcome, so this isn't a combat scene - that would requiring draining the character's Luck Pts in order to have a better outcome than the one already rolled on the dice.

It actually feels much more simple at the game table, and probably stops the development of individual house rulings for such things.
Due to the longevity of CoC however, many GMs just stuck with their own house rulings and haven't seen the need to update to CoC 7E.
Which is fair enough, it's pretty easy to run CoC 7E supplements with earlier editions of CoC, and vice versa :thumbsup:
 
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Yeah as far as I know, you may try a different approach, but the actual skill would be the same skill you initially rolled. Except with the risk of a failure causing a serious consequence, akin to an automatic fumble.
I don't play 7e, but my understanding was that the idea grew out of a common house rule for repeated attempts at a skill. Like having another go at Drive during a chase, with the risk of some further misfortune that might damage the car or completely lose track of the target.
The example in the 7e book has a subsequent failed use of Accounting to decipher a ledger causing an ink spill on the ledger... which I thought was pretty stupid.

Getting a librarian to help after a failed Library Roll seems more akin to hiring an NPC to pick a lock for you.
 
That doesn't seem like 'pushing' to me... it's not a retry of the same skill, it's a whole different approach to the problem... though I don't think you have to try to seduce a librarian to get one to assist on a book search.
Maybe it's not. I've not played 7e nearly enough:thumbsup:.
Also, I was picturing the librarian as a nice lady in her 50ies which just wants you to not damage her books and return them on time, not in you...in other words, the "charming smile" was meant as just a way to seem cute/fellow book-lover/whatever that would make her actually help a (likely weird) request:thumbsup:.

Getting a librarian to help after a failed Library Roll seems more akin to hiring an NPC to pick a lock for you.
Well, if it works, why not:grin:?

Yeah as far as I know, you may try a different approach, but the actual skill would be the same skill you initially rolled. Except with the risk of a failure causing a serious consequence, akin to an automatic fumble.

Trying a completely different approach would likely involve rolling a new skill. However, depending upon the logics of the situation, there may be a conseuence for that particular character returning to the issue, such as now requiring a Hard Success or something like that.
Heh, I'm not sure if the GMs I've played with had noticed the part about "having to roll the same skill". As I said, I need more 7e time...such issues are always noticed with more experience with the system:devil:!
 
Maybe it's not. I've not played 7e nearly enough:thumbsup:.
Also, I was picturing the librarian as a nice lady in her 50ies which just wants you to not damage her books and return them on time, not in you...in other words, the "charming smile" was meant as just a way to seem cute/fellow book-lover/whatever that would make her actually help a (likely weird) request:thumbsup:.


Well, if it works, why not:grin:?


Heh, I'm not sure if the GMs I've played with had noticed the part about "having to roll the same skill". As I said, I need more 7e time...such issues are always noticed with more experience with the system:devil:!
Someone mention libraries? :hehe:

2bae22c8-47b6-4bc2-8e8a-00161883d99c_text.gif
 
Heh, I'm not sure if the GMs I've played with had noticed the part about "having to roll the same skill". As I said, I need more 7e time...such issues are always noticed with more experience with the system:devil:!
I don't know for sure that's a requirement in 7e. It's just my interpretation after one read through.
Flirting with the librarian, regardless of age, seems like a valid maneuver in case you want to someday get into the 'special collections' area after hours.
 
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I don't know for sure that's a requirement in 7e. It's just my interpretation after one read through.
Well, and not needing it is my interpretation after one read-through...:grin:
One of us got it wrong, no big deal. I'll re-read it before playing the game again...so hopefully soon?

Flirting with the librarian, regardless of age, seems like a valid maneuver in case you want to someday get into the 'special collections' area after hours.
But then you might get distracted from reading:tongue:!
 
This would only work in a straight roll under. In Mythras, for example, this would mean that you would have less chance of winning an opposed roll, as rolls within the same success band are won by the higher roll that is still under skill (price is right, or blackjack). If you are going with a simple roll it might work though.

It would also mean you would have to invent a mode for failure if you relied on, say 96-100, as always failure. And if you gave a high enough skill, you can’t lose (90+ skill, step down that die to a d8+d10 instead of 2d10).

it works pretty well on the other end, as it only introduces new options that are out of normal range (11 or 12)
Oh certainly, it is just another way to do it.

I particularly dislike conflicting modifier mechanics, roll under but not too much...makes modifiers that help you roll under are good until they are not...I get the game mechanics aspect of it can be interesting but it buggers my suspension of disbelief.
 
Oh certainly, it is just another way to do it.

I particularly dislike conflicting modifier mechanics, roll under but not too much...makes modifiers that help you roll under are good until they are not...I get the game mechanics aspect of it can be interesting but it buggers my suspension of disbelief.
Wait, what? What modifiers that help you roll under "are good until they're not":shock:?
Sorry, I don't think that even makes sense...:shade:
 
Wait, what? What modifiers that help you roll under "are good until they're not":shock:?
Sorry, I don't think that even makes sense...:shade:
I may well have completely misunderstand the mechanic, but thought it was one where in a contest you both need to roll under your skill but the person who rolls highest but under wins.

Thus, if I had some gear or benefit that gave me a -10% modifier say (it helps me succeed because it helps me roll under), in a contested situation it could actually hurt me.

Example: say we both need to roll 50 or under. I roll a 49 and my opponent rolls a 48, so I "win" as under but closest. Now say I have this wonderful thing that helps me succeed and gives me a -10% modifier. In that case my roll of 49 becomes 39 and I lose. So a modifier that is supposed to make me do it better actually made me lose.

The greater the modifier the greater the conflict between the "meaning" of a modifier and the actual game mechanic. If that is what happens, then yes it doesn't make sense or more precisely the actual outcome given by the mechanics conflicts with the stated effected of a modifier. Why I am not a fan of it if that is the way it works.
 
I may well have completely misunderstand the mechanic, but thought it was one where in a contest you both need to roll under your skill but the person who rolls highest but under wins.

Thus, if I had some gear or benefit that gave me a -10% modifier say (it helps me succeed because it helps me roll under), in a contested situation it could actually hurt me.

Example: say we both need to roll 50 or under. I roll a 49 and my opponent rolls a 48, so I "win" as under but closest. Now say I have this wonderful thing that helps me succeed and gives me a -10% modifier. In that case my roll of 49 becomes 39 and I lose. So a modifier that is supposed to make me do it better actually made me lose.

The greater the modifier the greater the conflict between the "meaning" of a modifier and the actual game mechanic. If that is what happens, then yes it doesn't make sense or more precisely the actual outcome given by the mechanics conflicts with the stated effected of a modifier. Why I am not a fan of it if that is the way it works.
Oh, right. Some of the d100 mechanics systems use the roll under but highest under wins in an opposed roll. Though in that case, a Special roll beats a success roll and a Critical roll beats a Special or a success. I'm forgetting which d100 system does and which doesn't do that now. I've also forgotten if whether or not the roll higher but successfully is also a part of the Special and Critical rolls as well.

Example, if I have a chance for a Critical chance of 8% or under and you have a 5% chance of a Critical and we both roll Crits in an Opposed roll, whether or not the "highest" rolled Critical beats the other not. I roll a 3% but you roll 5%, do you win? You should under the highest rolled success (in this case highest rolled Critical success), but I'm not sure. Mostly because in the last six months I've read dozens of mechanics systems on a tear. Just deep diving repeatedly and when you're reading but not playing currently the d100BRP mechanics systems you tend to mix them up or at least I do. lol

If I was actually getting a chance to play it would be different. <grumble>
 
...

Example, if I have a chance for a Critical chance of 8% or under and you have a 5% chance of a Critical and we both roll Crits in an Opposed roll, whether or not the "highest" rolled Critical beats the other not. I roll a 3% but you roll 5%, do you win? ...
Personally I like things to work in one direction, so the person who rolled a 3% rolled 5 under their target number and thus wins because the person who rolled 5% just made their target. I like it to be if a roll under is good, then the lower the better, thus a modifier that helps lower your roll is always a good thing.
 
Personally I like things to work in one direction, so the person who rolled a 3% rolled 5 under their target number and thus wins because the person who rolled 5% just made their target. I like it to be if a roll under is good, then the lower the better, thus a modifier that helps lower your roll is always a good thing.
That's generally how I felt when I first read it. It just felt that the lowest roll should win the contest. After thinking about it over time though, I've come around. It makes higher skill more meaningful in a larger way in my opinion.
 
That's generally how I felt when I first read it. It just felt that the lowest roll should win the contest. After thinking about it over time though, I've come around. It makes higher skill more meaningful in a larger way in my opinion.
I have no issues with how it interacts with skills, it is how it interacts with modifiers. In reality it seems way too metagamey for me because there are other ways to make higher skill more meaningful. A simpler way to make higher skill more meaningful is to simply say the lower under the target number the better or if I have a skill or target of 50%, and if your roll 5% or under get a special result (i.e. roll 1/10th under your target number).

Of course all of my concerns would be addressed by simply making it roll under but closest to one's target number (instead of ones skill before modification).

If anything I believe the mechanic actually favors the worse target number person as once they meet the bar of rolling under, their chance of winning is as good as the higher skilled (or better target number) person, it is a way to counter the effect of high skill.
 
Example: say we both need to roll 50 or under. I roll a 49 and my opponent rolls a 48, so I "win" as under but closest. Now say I have this wonderful thing that helps me succeed and gives me a -10% modifier. In that case my roll of 49 becomes 39 and I lose. So a modifier that is supposed to make me do it better actually made me lose.
On the other hand, applying a bonus to the target number works perfectly for this - the guy with the 49 can roll a 50-60 and beat the 48 in a way he cannot win against.
A simpler way to make higher skill more meaningful is to simply say the lower under the target number the better or if I have a skill or target of 50%, and if your roll 5% or under get a special result (i.e. roll 1/10th under your target number).
Unless I’m missing something (only half paying attention over here) If the target number is not tied to a skill, this won’t really have any impact. Target number of 25, a person with a 25 and a person with a 50 have them same chance - 25%
If course all of my concerns would be addressed by simply making it roll under but closest to one's target number (instead of ones skill before modification).
Yah this is the blackjack or price is right mechanism.

my group struggled a bit with this for a while. Took a while to beat it into them.
 
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I may well have completely misunderstand the mechanic, but thought it was one where in a contest you both need to roll under your skill but the person who rolls highest but under wins.

Thus, if I had some gear or benefit that gave me a -10% modifier say (it helps me succeed because it helps me roll under), in a contested situation it could actually hurt me.
No, it cannot, and I'm sorry to say, you have misunderstood the mechanic:shade:.
The -10 modifier, which is a penalty, is applied to your skill number.
Conversely, when you have a +10 modifier, it can only help you. Because the guy who had merely 8% lower skill now has 18% less, and that's roughly* 18% chance that he couldn't oppose the roll at all.


*Roughly, because he could well roll a critical vs. your normal success, for example. But then less skilled people do happen to win contests IRL as well, with some luck:thumbsup:.


Example: say we both need to roll 50 or under. I roll a 49 and my opponent rolls a 48, so I "win" as under but closest. Now say I have this wonderful thing that helps me succeed and gives me a -10% modifier. In that case my roll of 49 becomes 39 and I lose. So a modifier that is supposed to make me do it better actually made me lose.
In no d100 system that I remember is there a modifier that's applied to your roll.
Actually, scratch that...there is one such case in Unknown Armies 2e, but it's a +X and represents increased difficulty which also should make your action more efficient, if you succeed. It's an aimed shot mechanic, since in UA 2e the damage is the sum of the numbers on the dieroll. That also means it doesn't apply to opposed rolls, because attacking isn't an opposed roll (although UA also uses blackjack).
So no, your hypothetical case...simply cannot happen, unless it's a houserule. But then the problem is with the houserule, not the principle of rolling under - blackjack or not:devil:.
 
Oh, right. Some of the d100 mechanics systems use the roll under but highest under wins in an opposed roll. Though in that case, a Special roll beats a success roll and a Critical roll beats a Special or a success. I'm forgetting which d100 system does and which doesn't do that now. I've also forgotten if whether or not the roll higher but successfully is also a part of the Special and Critical rolls as well.

Example, if I have a chance for a Critical chance of 8% or under and you have a 5% chance of a Critical and we both roll Crits in an Opposed roll, whether or not the "highest" rolled Critical beats the other not. I roll a 3% but you roll 5%, do you win?
In a word - yes, unless you're only comparing degrees of success:tongue:!
Of course, higher skill also gives you the ability to roll a higher critical your opponent can't oppose on any roll...and this also applies if the skill is higher due to a modifier:gunslinger:.
 
Add me into the crowd that likes “flip flopping” the d100 roll favourably (or unfavourably). Super simple, but I don’t know if the statistics are any good.
 
Add me into the crowd that likes “flip flopping” the d100 roll favourably (or unfavourably). Super simple, but I don’t know if the statistics are any good.
The statistics are great, especially since it's an easy kind of bonus that has a "bell curve":thumbsup:.
 
Add me into the crowd that likes “flip flopping” the d100 roll favourably (or unfavourably). Super simple, but I don’t know if the statistics are any good.
Up thread (maybe the first post) there is a link to a post that gives the statistics.
 
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